1. Field of the Invention
The present invention relates to stabilizers for dyestuffs. More particularly, the present invention relates to stabilizers or precursors for dyestuffs which are useful in the dyeing of both natural and synthetic fibers. Even more particularly, the present invention relates to dyestuff precursors or stabilizers, prepared by a condensation reaction in a non-acid medium, which are useful in the preparation of azoic dyes. The invention also relates to the dyes prepared therefrom, the dyes being efficacious in the dyeing of both natural and synthetic fibers.
2. Prior Art
The prior art is replete with azoic compositions useful in the dyeing of fibrous material. Generally speaking, these compositions comprise azoitized amino compounds which are prepared in the presence of an acid medium. The predominant bulk of these compositions or dyestuffs are usually derived from aniline and related compounds. See, inter alia, U.S. Pat. No. 1,858,623; 1,979,327; and the like.
With the advent of new synthetic textiles and fibers the art has given way to the development of dyestuffs which must be more compatible with these new fibers. Thus, the basic azo dyestuffs must be stabilized or otherwise complexed with other compounds to render them more receptive by the fiber. Concomitantly, the art has developed more sophisticated dyestuffs designed to achieve these same purposes.
However, the new dyestuffs being produced are generally quite exotic and, therefore, expensive and difficult to manufacture in industrial quantities. Moreover, the dyestuffs being produced are incapable of being used with a plurality of fibrous materials. In other words, a dyestuff useful for dyeing a polyester fabric will, generally, be incapable of dyeing a natural fiber, such as, cotton or wool, and vice versa.
Thus, a major advance in the art would be provided by new dyestuffs useful in the dyeing of both natural and synthetic fibers. There would also be a major advance in the art if such dyestuffs could be manufactured inexpensively from readily available chemicals. It is these ends to which the present invention is directed.